It is good that you're getting numbers, and getting comfortable with approaching/chatting up girls! This is an essential part that must be taken up in your growth process. Doing this helped me get to the point where I can approach women and talk to them without even thinking about it, and it will do the same for you as well.
As far as getting numbers themselves, like others have said, I will say that they don't mean much these days. Many of us here have learned this lesson, that rarely does a number pan out to a date if you just went up to the girl, talked to her for a minute or two and popped the number question. This is for one simple reason: She doesn't KNOW you.
Put yourself in her shoes. Here she is, this random guy comes up to her, makes some small talk, and before she knows it he wants her number for some reason. Okay, fine. Then he calls her up and wants to go on a date, but who is this guy again? He could be an axe murderer, he seemed to be confident, but not enough could be determined about him. Besides, 2 other guys have done the same thing today anyhow! Yes, sometimes it will work out and work out quite well (sometimes people just 'click'), but I find that's the exception not the rule.
These days I don't do cold pickups much at all anymore. Sure, I go up to girls I've never met and chat them up for the hell of it all the time, but I rarely get the number, unless I find them very interesting and I sense a good connection between us. I like to get to know a girl better, and especially have her get to know me and naturally get to like me (i.e. be attracted to me) and then we can get together and do stuff in groups of friends, get her comfortable, then isolated, and go from there. That's what I like and what I'm getting better at, it might be different for you and everyone's technique is different, there is no miracle way to get chicks, it all matters on your personality and temperment.
You might find the "Juggler Method" quite interesting. It centers on being very outgoing and friendly to about everyone, and through this charisma women will be naturally attracted. I have found the same, if you're funny and outgoing, women love that and will naturally be attracted to you.
Hopefully some of this half-drunken rambling was useful to you!
Good luck!